Studies will be conducted on the formation of intimal hyperplasia and atherosclerosis in artery vein and venous grafts. Intimal hyperplasia will be produced in animal models by deendothelialization of native vasculature by a balloon catheter. Vein grafted into the arterial system will be used for production of graft hyperplasia. The adhesion of platelets to these vessels will be studied as well as the synthesis of lipids including prostaglandins. Attempts will be made to inhibit intimal hyperplasia by drug treatment.